[PATCH] powerpc: Wire up clone3 syscall

From: Michael Ellerman
Date: Mon Jul 22 2019 - 09:22:46 EST


Wire up the new clone3 syscall added in commit 7f192e3cd316 ("fork:
add clone3").

This requires a ppc_clone3 wrapper, in order to save the non-volatile
GPRs before calling into the generic syscall code. Otherwise we hit
the BUG_ON in CHECK_FULL_REGS in copy_thread().

Lightly tested using Christian's test code on a Power8 LE VM.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/unistd.h | 1 +
arch/powerpc/kernel/entry_64.S | 5 +++++
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
3 files changed, 7 insertions(+)

diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 68473c3c471c..b0720c7c3fcf 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -49,6 +49,7 @@
#define __ARCH_WANT_SYS_FORK
#define __ARCH_WANT_SYS_VFORK
#define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_CLONE3

#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_UNISTD_H_ */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d9105fcf4021..0a0b5310f54a 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -487,6 +487,11 @@ _GLOBAL(ppc_clone)
bl sys_clone
b .Lsyscall_exit

+_GLOBAL(ppc_clone3)
+ bl save_nvgprs
+ bl sys_clone3
+ b .Lsyscall_exit
+
_GLOBAL(ppc32_swapcontext)
bl save_nvgprs
bl compat_sys_swapcontext
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index f2c3bda2d39f..6886ecb590d5 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -516,3 +516,4 @@
432 common fsmount sys_fsmount
433 common fspick sys_fspick
434 common pidfd_open sys_pidfd_open
+435 common clone3 ppc_clone3
--
2.20.1